This invention relates to a brake failure warning device and, more particularly, to a device for indicating the condition of the brake linings in an automotive vehicle without requiring visual examination of the brakes.
Safe driving requires that the brake linings comprising the brakes of an automotive vehicle be in good condition so as to ensure satisfactory braking action. However, the wear rate of the brake linings varies depending on several factors including the manner in which the vehicle is driven, thereby making it difficult to estimate without visual examination the condition of the linings. Therefore, periodic time consuming and expensive inspections are needed, even though the linings may be satisfactory, since the brakes cannot be visually examined without removing the wheels and brake housings.
As a result, brake failure warning detectors have been developed which inform the driver of the condition of the linings. These detectors include apparatus that sense when the linings have worn to a point where replacement is necessary and then signal the driver, via an alarm on the dashboard of the vehicle, of this fact. With such detectors, periodic brake inspections are unnecessary and the driver is assured the linings are adequate.
Such known detectors are generally complex in design and operation, and are expensive to manufacture. In addition, many of these detectors require that the brake pedal be depressed before a circuit is closed to activate an alarm. Since the brake pedal is usually not depressed until after the vehicle is in motion, the operator will be unaware that his brakes are defective until he is required to apply them. This type of operation is often unsatisfactory and may be dangerous under certain conditions.
The present invention, on the other hand, provides a brake failure warning device which has few parts, is simple in operation and inexpensive to make. Furthermore, this invention may be easily installed either at the factory when the vehicle is built, or by a user after it has been delivered.